can it be something that happens suddenly enough that you can't get to a hospital?

I would say in most instances, yes. It isn't like everything is completely normal and then all of the sudden you are giving birth, there are generally stomach pains and they get pretty bad and then of course there is bleeding. If you are pregnant though, your doctor usually will tell you to contact them/their office if you feel anything really unusual pains/bleeding. If you are bleeding and do get in contact with them they will tell you to call 911.

Premees can survive that young, it just depends. Also no, the hospital can't legally give your information to anyone other than you without your consent (unless you are under age which isnt the case here). Also, she was 30-something at the time so she couldn't have been on her parent insurance. Paying for treatment was going to have to be up to her.

So just to recap, a fetus that old could have survived if she would have gone to the hospital very early on but the chances of survival went down exponentially leading up to the birth. Reasonably, her parents could have never found out about the pregnancy because the Dr's/nursing staff couldn't divulge any information about her without her consent (weather she knew that or not is questionable). Her medical bills would have been paid by her because she couldn't be on her parents insurance due to her age (I think they just pushed the cut off to 24? for college students but I could be wrong on that number).

The right (correct) thing to do in this situation is go to the hospital, even if it's too late. That way they could fill out a death certificate and properly dispose of the human remains, see this as not putting it into a dumpster. Weather she could pay or not shouldn't even be a factor because a Hospital in the United States will not turn you down for any reason. Hindsight is 20/20 obviously and I don't really want to debate what a baby is vs. what a fetus is, but I hope this information was useful to you and hopefully you will be a little more informed on the subject!